one in three adults worldwide fails to do the recommended 150 minutes of moderate aerobic physical activity per week. In the UK two out of three adults don’t manage it.

So rather than stressing the health benefits of exercise, the Lancet researchers have opted to show the harm caused by inactivity. They estimate lack of exercise is responsible for about 5.3m deaths a year – about the same number as smoking.

This is based on estimates of the impact on inactivity on coronary heart disease, Type 2 diabetes, and two specfic cancers – breast and bowel – where lack of exercise is a major risk factor.

Worldwide, we estimate that physical inactivity causes 6% (ranging from 3·2% in southeast Asia to 7·8% in the eastern Mediterranean region) of the burden of disease from coronary heart disease, 7% (3·9—9·6) of type 2 diabetes, 10% (5·6—14·1) of breast cancer, and 10% (5·7—13·8) of colon cancer. Inactivity causes 9% (range 5·1—12·5) of premature mortality, or more than 5·3 million of the 57 million deaths that occurred worldwide in 2008. If inactivity were not eliminated, but decreased instead by 10% or 25%, more than 533 000 and more than 1·3 million deaths, respectively, could be averted every year. We estimated that elimination of physical inactivity would increase the life expectancy of the world’s population by 0·68 (range 0·41—0·95) years.

[…] The link between the extremely rapid rise in obesity and the overuse of anti-biotics is in need of much more study. It seems a possible contributing factor but there is much more data needed to confirm such a link. And other factors still seem dominant to me: increase in caloric intake and decrease in physical activity. […]

The conclusions are based on the independent review of more than 1000 scientific
papers from studies on five continents. The reviewed studies analyse the carcinogenicity of various pollutants present in outdoor air pollution, especially particulate matter and transportation-related pollution.